Merge #6750

6750: Remove documentation query, move doc handling to attributes r=matklad a=Veykril

Fixes #3182

Removes the documentation query in favor of `Attrs::docs`. Attrs already handlded doc comments partially but the alloc saving check was wrong so it only worked when other attributes existed as well. Unfortunately the `new` constructor has to do an intermediate allocation now because we need to keep the order of mixed doc attributes and doc comments.

I've also partially adjusted the `hover` module to have its tests check the changes, it still has some `HasSource` trait usage due to the `ShortLabel` trait usage, as that is only implemented on the Ast parts and not the Hir, should this ideally be implemented for the Hir types as well?(would be a follow up PR of course)

Co-authored-by: Lukas Wirth <[email protected]>

5 files changed, 57 insertions, 141 deletions

diff --git a/crates/hir_def/src/attr.rs b/crates/hir_def/src/attr.rs
index b2ce7ca3c..12f4b02e2 100644
--- a/crates/hir_def/src/attr.rs
+++ b/crates/hir_def/src/attr.rs
@@ -5,10 +5,11 @@ use std::{ops, sync::Arc};
 use cfg::{CfgExpr, CfgOptions};
 use either::Either;
 use hir_expand::{hygiene::Hygiene, AstId, InFile};
+use itertools::Itertools;
 use mbe::ast_to_token_tree;
 use syntax::{
     ast::{self, AstNode, AttrsOwner},
-    SmolStr,
+    AstToken, SmolStr,
 };
 use tt::Subtree;
 
@@ -21,6 +22,22 @@ use crate::{
     AdtId, AttrDefId, Lookup,
 };
 
+/// Holds documentation
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Documentation(String);
+
+impl Documentation {
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+impl Into<String> for Documentation {
+    fn into(self) -> String {
+        self.0
+    }
+}
+
 #[derive(Default, Debug, Clone, PartialEq, Eq)]
 pub struct Attrs {
     entries: Option<Arc<[Attr]>>,
@@ -93,18 +110,25 @@ impl Attrs {
     }
 
     pub(crate) fn new(owner: &dyn AttrsOwner, hygiene: &Hygiene) -> Attrs {
-        let docs = ast::CommentIter::from_syntax_node(owner.syntax()).doc_comment_text().map(
-            |docs_text| Attr {
-                input: Some(AttrInput::Literal(SmolStr::new(docs_text))),
-                path: ModPath::from(hir_expand::name!(doc)),
-            },
-        );
-        let mut attrs = owner.attrs().peekable();
-        let entries = if attrs.peek().is_none() {
+        let docs = ast::CommentIter::from_syntax_node(owner.syntax()).map(|docs_text| {
+            (
+                docs_text.syntax().text_range().start(),
+                docs_text.doc_comment().map(|doc| Attr {
+                    input: Some(AttrInput::Literal(SmolStr::new(doc))),
+                    path: ModPath::from(hir_expand::name!(doc)),
+                }),
+            )
+        });
+        let attrs = owner
+            .attrs()
+            .map(|attr| (attr.syntax().text_range().start(), Attr::from_src(attr, hygiene)));
+        // sort here by syntax node offset because the source can have doc attributes and doc strings be interleaved
+        let attrs: Vec<_> = docs.chain(attrs).sorted_by_key(|&(offset, _)| offset).collect();
+        let entries = if attrs.is_empty() {
             // Avoid heap allocation
             None
         } else {
-            Some(attrs.flat_map(|ast| Attr::from_src(ast, hygiene)).chain(docs).collect())
+            Some(attrs.into_iter().flat_map(|(_, attr)| attr).collect())
         };
         Attrs { entries }
     }
@@ -140,6 +164,24 @@ impl Attrs {
             Some(cfg) => cfg_options.check(&cfg) != Some(false),
         }
     }
+
+    pub fn docs(&self) -> Option<Documentation> {
+        let docs = self
+            .by_key("doc")
+            .attrs()
+            .flat_map(|attr| match attr.input.as_ref()? {
+                AttrInput::Literal(s) => Some(s),
+                AttrInput::TokenTree(_) => None,
+            })
+            .intersperse(&SmolStr::new_inline("\n"))
+            .map(|it| it.as_str())
+            .collect::<String>();
+        if docs.is_empty() {
+            None
+        } else {
+            Some(Documentation(docs.into()))
+        }
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -160,8 +202,10 @@ impl Attr {
     fn from_src(ast: ast::Attr, hygiene: &Hygiene) -> Option<Attr> {
         let path = ModPath::from_src(ast.path()?, hygiene)?;
         let input = if let Some(lit) = ast.literal() {
-            // FIXME: escape? raw string?
-            let value = lit.syntax().first_token()?.text().trim_matches('"').into();
+            let value = match lit.kind() {
+                ast::LiteralKind::String(string) => string.value()?.into(),
+                _ => lit.syntax().first_token()?.text().trim_matches('"').into(),
+            };
             Some(AttrInput::Literal(value))
         } else if let Some(tt) = ast.token_tree() {
             Some(AttrInput::TokenTree(ast_to_token_tree(&tt)?.0))
diff --git a/crates/hir_def/src/db.rs b/crates/hir_def/src/db.rs
index 6d694de11..7f250da33 100644
--- a/crates/hir_def/src/db.rs
+++ b/crates/hir_def/src/db.rs
@@ -10,7 +10,6 @@ use crate::{
     attr::Attrs,
     body::{scope::ExprScopes, Body, BodySourceMap},
     data::{ConstData, FunctionData, ImplData, StaticData, TraitData, TypeAliasData},
-    docs::Documentation,
     generics::GenericParams,
     import_map::ImportMap,
     item_tree::ItemTree,
@@ -105,11 +104,6 @@ pub trait DefDatabase: InternDatabase + AstDatabase + Upcast<dyn AstDatabase> {
     #[salsa::invoke(LangItems::lang_item_query)]
     fn lang_item(&self, start_crate: CrateId, item: SmolStr) -> Option<LangItemTarget>;
 
-    // FIXME(https://github.com/rust-analyzer/rust-analyzer/issues/2148#issuecomment-550519102)
-    // Remove this query completely, in favor of `Attrs::docs` method
-    #[salsa::invoke(Documentation::documentation_query)]
-    fn documentation(&self, def: AttrDefId) -> Option<Documentation>;
-
     #[salsa::invoke(ImportMap::import_map_query)]
     fn import_map(&self, krate: CrateId) -> Arc<ImportMap>;
 }
diff --git a/crates/hir_def/src/docs.rs b/crates/hir_def/src/docs.rs
deleted file mode 100644
index 3e59a8f47..000000000
--- a/crates/hir_def/src/docs.rs
+++ /dev/null
@@ -1,121 +0,0 @@
-//! Defines hir documentation.
-//!
-//! This really shouldn't exist, instead, we should deshugar doc comments into attributes, see
-//! https://github.com/rust-analyzer/rust-analyzer/issues/2148#issuecomment-550519102
-
-use std::sync::Arc;
-
-use either::Either;
-use itertools::Itertools;
-use syntax::{ast, SmolStr};
-
-use crate::{
-    db::DefDatabase,
-    src::{HasChildSource, HasSource},
-    AdtId, AttrDefId, Lookup,
-};
-
-/// Holds documentation
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct Documentation(Arc<str>);
-
-impl Into<String> for Documentation {
-    fn into(self) -> String {
-        self.as_str().to_owned()
-    }
-}
-
-impl Documentation {
-    fn new(s: &str) -> Documentation {
-        Documentation(s.into())
-    }
-
-    pub fn from_ast<N>(node: &N) -> Option<Documentation>
-    where
-        N: ast::DocCommentsOwner + ast::AttrsOwner,
-    {
-        docs_from_ast(node)
-    }
-
-    pub fn as_str(&self) -> &str {
-        &*self.0
-    }
-
-    pub(crate) fn documentation_query(
-        db: &dyn DefDatabase,
-        def: AttrDefId,
-    ) -> Option<Documentation> {
-        match def {
-            AttrDefId::ModuleId(module) => {
-                let def_map = db.crate_def_map(module.krate);
-                let src = def_map[module.local_id].declaration_source(db)?;
-                docs_from_ast(&src.value)
-            }
-            AttrDefId::FieldId(it) => {
-                let src = it.parent.child_source(db);
-                match &src.value[it.local_id] {
-                    Either::Left(_tuple) => None,
-                    Either::Right(record) => docs_from_ast(record),
-                }
-            }
-            AttrDefId::AdtId(it) => match it {
-                AdtId::StructId(it) => docs_from_ast(&it.lookup(db).source(db).value),
-                AdtId::EnumId(it) => docs_from_ast(&it.lookup(db).source(db).value),
-                AdtId::UnionId(it) => docs_from_ast(&it.lookup(db).source(db).value),
-            },
-            AttrDefId::EnumVariantId(it) => {
-                let src = it.parent.child_source(db);
-                docs_from_ast(&src.value[it.local_id])
-            }
-            AttrDefId::TraitId(it) => docs_from_ast(&it.lookup(db).source(db).value),
-            AttrDefId::MacroDefId(it) => docs_from_ast(&it.ast_id?.to_node(db.upcast())),
-            AttrDefId::ConstId(it) => docs_from_ast(&it.lookup(db).source(db).value),
-            AttrDefId::StaticId(it) => docs_from_ast(&it.lookup(db).source(db).value),
-            AttrDefId::FunctionId(it) => docs_from_ast(&it.lookup(db).source(db).value),
-            AttrDefId::TypeAliasId(it) => docs_from_ast(&it.lookup(db).source(db).value),
-            AttrDefId::ImplId(_) => None,
-        }
-    }
-}
-
-pub(crate) fn docs_from_ast<N>(node: &N) -> Option<Documentation>
-where
-    N: ast::DocCommentsOwner + ast::AttrsOwner,
-{
-    let doc_comment_text = node.doc_comment_text();
-    let doc_attr_text = expand_doc_attrs(node);
-    let docs = merge_doc_comments_and_attrs(doc_comment_text, doc_attr_text);
-    docs.map(|it| Documentation::new(&it))
-}
-
-fn merge_doc_comments_and_attrs(
-    doc_comment_text: Option<String>,
-    doc_attr_text: Option<String>,
-) -> Option<String> {
-    match (doc_comment_text, doc_attr_text) {
-        (Some(mut comment_text), Some(attr_text)) => {
-            comment_text.push_str("\n");
-            comment_text.push_str(&attr_text);
-            Some(comment_text)
-        }
-        (Some(comment_text), None) => Some(comment_text),
-        (None, Some(attr_text)) => Some(attr_text),
-        (None, None) => None,
-    }
-}
-
-fn expand_doc_attrs(owner: &dyn ast::AttrsOwner) -> Option<String> {
-    let mut docs = String::new();
-    owner
-        .attrs()
-        .filter_map(|attr| attr.as_simple_key_value().filter(|(key, _)| key == "doc"))
-        .map(|(_, value)| value)
-        .intersperse(SmolStr::new_inline("\n"))
-        // No FromIterator<SmolStr> for String
-        .for_each(|s| docs.push_str(s.as_str()));
-    if docs.is_empty() {
-        None
-    } else {
-        Some(docs)
-    }
-}
diff --git a/crates/hir_def/src/lib.rs b/crates/hir_def/src/lib.rs
index b41c5acb2..02ed30e4d 100644
--- a/crates/hir_def/src/lib.rs
+++ b/crates/hir_def/src/lib.rs
@@ -31,7 +31,6 @@ pub mod adt;
 pub mod data;
 pub mod generics;
 pub mod lang_item;
-pub mod docs;
 
 pub mod expr;
 pub mod body;
diff --git a/crates/hir_def/src/nameres/tests/mod_resolution.rs b/crates/hir_def/src/nameres/tests/mod_resolution.rs
index ef6f85e15..e80b593aa 100644
--- a/crates/hir_def/src/nameres/tests/mod_resolution.rs
+++ b/crates/hir_def/src/nameres/tests/mod_resolution.rs
@@ -372,7 +372,7 @@ fn module_resolution_explicit_path_mod_rs_with_win_separator() {
     check(
         r#"
 //- /main.rs
-#[path = "module\bar\mod.rs"]
+#[path = r"module\bar\mod.rs"]
 mod foo;
 
 //- /module/bar/mod.rs